Calculate how long it will take to reach your target weight from a calorie deficit, with daily and weekly deficit targets and an estimated goal date.
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Units
8 kg
To lose
16
Weeks
550
Daily deficit (kcal)
3850
Weekly deficit (kcal)
| Weight to lose | 8 kg / 17.6 lbs |
| Time to goal | 16 weeks (~4 months) |
| Estimated goal date | July 5, 2026 |
| Daily calorie deficit | 550 kcal/day |
| Weekly calorie deficit | 3850 kcal/week |
Also in Goal Planning
Goal Planning
This calculator estimates how long it will take to reach a target weight based on a chosen weekly calorie deficit. It also shows the daily and weekly calorie reduction required, and projects an estimated goal date.
One kilogram of body fat stores approximately 7,700 kcal of energy. To lose 0.5 kg per week you need a deficit of about 3,850 kcal per week — or 550 kcal per day. To lose 1 kg per week you need roughly 7,700 kcal per week deficit, or about 1,100 kcal per day.
Most guidelines recommend a maximum loss rate of 0.5–1 kg per week for sustainable fat loss with minimal muscle loss. Faster rates often involve muscle breakdown and are harder to maintain. Slow rates (0.25 kg/week) are easier to maintain and generally lead to better long-term outcomes.
As you lose weight, your resting metabolic rate decreases (metabolic adaptation), meaning the same deficit produces less loss over time. Protein intake and resistance training help preserve lean mass during a deficit.
Frequently asked questions
A deficit of 500 kcal per day leads to approximately 0.5 kg per week of fat loss — a commonly recommended starting point. Use a TDEE calculator to find your maintenance calories, then subtract the deficit.
Rates above 1 kg/week typically require very large deficits (over 1,000 kcal/day) and can lead to muscle loss, nutritional deficiencies, and fatigue. Such rates should only be pursued under medical supervision.
Related
These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.
Estimate a daily calorie deficit and target intake for slow, moderate, or aggressive fat-loss pacing.
Estimate total daily energy expenditure from age, body size, sex, and activity level, then compare maintenance, cutting, and bulking calories.
See ideal body weight estimates from four classic medical formulas (Hamwi, Devine, Robinson, Miller) based on your height and sex.
Estimate body fat percentage using the US Navy circumference method — measure neck, waist, and hips to get fat mass, lean mass, and an ACE fitness category.
